SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '3d795151201183ddcecb108074f79f408f0252f0aea679346f533e5b148ab771' 
  AND token = 'Px3kN7N4FZ/SfSnUFSoLGlaSikXa/7zUEZgyP94pQPs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}